I. TGM I: Summary of Features

I.F. Significant Differences from the First Edition

Probably the most significant change in TGM I has been in the
addition of 1,937 postable and 1,755 non-postable terms. Additions and changes
to the vocabulary are a direct outgrowth of the cataloging that has been going
on in P&P and a few contributing organizations over the past seven years. The
cataloging of groups of photographs, including many relating to Native Americans,
and a program to catalog single items for which orders for reproduction have been
received--ranging from Currier & Ives prints and Civil War drawings
and photographs to 20th century fine prints and World War II posters--have
resulted in many new terms. Other recent projects have focused on cataloging
groups of architectural drawings and architectural photographs. These
cataloging ventures have resulted in the addition of more specific vocabulary
(Houses has been added as a narrower term to
Dwellings, for instance). Coinciding as they did with the
publication of the AAT, such projects have also spurred a re-examination of the terms used for buildings and sites and of the relationships that exist among
them. Appropriately enough, this has resulted in a new structure, founded on the
concept of Facilities, a broader concept than Buildings. This
new structure attempts to incorporate many terms that were previously "orphans"
(i.e., they had no broader term), while remaining flexible enough to be used in
situations that show combinations of site, structure, and activities
characteristic of a particular type of facility. A corresponding structure for
Architectural & site components has also been developed.

Changes in terminology, while inevitable, can be time-consuming to
implement in indexing systems or, if not fully implemented, can place burdens on
the users who must then search under old and new terms. While some term
changes have been necessary, particularly in the context of the work on
Facilities, an attempt has been made to keep major changes to a minimum and to alert users of TGM I to changes that have occurred by recording history notes under changed terms.

The lists of topical subdivisions used by P&P have been restructured
and expanded since the first edition; they include, for the first time,
subdivisions used with names of corporate bodies and names of wars (see Appendices A through D). Other differences from
the first
edition include greater allowance for geographic and nationality subdivision (see
Section III for a discussion of subdivision
practice). Public and cataloger's notes that were found to be too local or
limited in their application have been eliminated or altered. Cataloging
examples have been added to illustrate some of the indexing principles and
practices employed by P&P catalogers.